As containers made of resin, such as PET (polyethylene terephthalate), narrow-mouthed containers for drinking have been common. In recent, years, the range of uses for resin containers has become expanded. Currently, there are not only narrow-mouthed containers for drinking, but also so-called jar type wide-mouthed containers, for example, for storage of foods or for cosmetics. The wide-mouthed container refers to a container in which the ratio of the outer diameter of the mouth (neck) to the outer diameter of a barrel is relatively high in comparison with the narrow-mouthed container for drinking. In particular, the container with the outer diameter of the mouth being, for example, 43 mm or more is generally called a wide-mouthed container.
Such a wide-mouthed container is produced using a preform of a larger size than a preform for producing a narrow-mouthed container. Thus, the preform for producing a wide-mouthed container (will hereinafter be referred to as a wide-mouthed preform) is relatively heavyweight. The size (outer diameter) of a flange to be provided at the mouth of the wide-mouthed preform is relatively small. That is, the ratio of the diameter of the flange to the outer diameter of the mouth is relatively low. In a state in which the preform is held, with the mouth facing upward, therefore, there has been a problem such that it is difficult to supply the wide-mouthed preform to a transport path provided in a crystallization device or a molding device, or to transport the wide-mouthed preform on the transport path.
In the field of wide-mouthed containers, there has been a desire for an increase in a filling volume, namely, further upsizing of a wide-mouthed container. To achieve the upsizing of the wide-mouthed container, it is also necessary to upsize a wide-mouthed preform. In this case, the above-mentioned problem with supply or transport is apt to occur.
To solve such a problem, the present applicant developed a mouth crystallization apparatus equipped with a device for holding wide-mouthed preforms, in an inverted state with the mouths facing downward, by transport members and transporting the transport members along a transport path (see Patent Document 1).
With this apparatus, the transport member has a transport stand to be supplied with the wide-mouthed preform in an inverted state, and is also equipped with a pushup portion, a core, etc, which can be raised and lowered by an elevating/lowering rod. The pushup portion and core are located above the transport stand when the elevating/lowering rod is at an ascent position, and they are located below the transport stand when the elevating/lowering rod is at a descent position. The wide-mouthed preform is supplied to the transport stand when the elevating/lowering rod is at the descent position, and is held by the transport member when the elevating/lowering rod is then raised to the ascent position.